The epithet "noteworthy" is applied to achievements in all branches of effort that rank among the members of any profession or calling as equal, at least, to that which an F.R.S. holds among scientific men. This affords a convenient and sufficiently definite standard of merit. I could think of none more appropriate when addressing scientific men, and it seems to have been generally understood in the desired sense. It includes more than a half of those whose names appear in the modern editions of "Who's Who," which are become less discriminate than the earlier ones. "Noteworthiness" is ascribed, without exception, to all whose names appear in the "Dictionary of National Biography," but all of these were dead before the date of the publication of that work and its supplement. Noteworthiness is also ascribed to those whose biographies appear in the "Encyclopaedia Britannica" (which includes many who are now alive), and, in other works, of equivalent authority. As those persons were considered by editors of the last named publications to be worthy of note, I have accepted them, on their authority, as noteworthy. CHAPTER III.--HIGHEST ORDER OF ABILITY. No attempt is made in this book to deal with the transmission of ability of the very highest order, as the data in hand do not furnish the required material, nor will the conclusions be re-examined at length that I published many years ago in "Hereditary Genius." Still, some explanation is desirable to show the complexity of the conditions that are concerned with the hereditary transmission of the highest ability, which, for the moment, will be considered as the same thing as the highest fame.